// Copyright (c) 2015-2019 Amanieu d'Antras and DGuco(杜国超).All rights reserved.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

#ifndef ASYNCXX_H_
# error "Do not include this header directly, include <async++.h> instead."
#endif

namespace stagefuture
{
namespace detail
{

// Internal implementation of parallel_for that only accepts a partitioner
// argument.
template<typename Partitioner, typename Func>
void internal_parallel_for(detail::scheduler &sched, Partitioner partitioner, const Func &func)
{
    // Split the partition, run inline if no more splits are possible
    auto subpart = partitioner.split();
    if (subpart.begin() == subpart.end()) {
        for (auto &&i: partitioner)
            func(std::forward<decltype(i)>(i));
        return;
    }

    // Run the function over each half in parallel
    auto &&t = stagefuture::local_spawn(sched, [&sched, &subpart, &func]
    {
        detail::internal_parallel_for(sched, std::move(subpart), func);
    });
    detail::internal_parallel_for(sched, std::move(partitioner), func);
    t.get();
}

} // namespace detail

// Run a function for each element in a range
template<typename Range, typename Func>
void parallel_for(detail::scheduler &sched, Range &&range, const Func &func)
{
    detail::internal_parallel_for(sched, stagefuture::to_partitioner(std::forward<Range>(range)), func);
}

// Overload with default scheduler
template<typename Range, typename Func>
void parallel_for(Range &&range, const Func &func)
{
    stagefuture::parallel_for(::stagefuture::default_scheduler(), range, func);
}

// Overloads with std::initializer_list
template<typename T, typename Func>
void parallel_for(detail::scheduler &sched, std::initializer_list<T> range, const Func &func)
{
    stagefuture::parallel_for(sched, stagefuture::make_range(range.begin(), range.end()), func);
}
template<typename T, typename Func>
void parallel_for(std::initializer_list<T> range, const Func &func)
{
    stagefuture::parallel_for(stagefuture::make_range(range.begin(), range.end()), func);
}

} // namespace stagefuture
